1. Technical Field
The present invention relates to switched communications networks providing voice mail services, more particularly to a system and method for providing communication between voice mail systems and other electronic mail systems using directory systems having speech recognition capabilities.
2. Background Art
Voice mail has become commnonplace not only in business usage but also on an individual telephone service subscriber basis through service from a central office. A voice mail system is a specialized computer that stores messages in digital form on a disk. The voice is generally digitized, usually at a much slower rate than the 64 Kb/s signal the central office uses in its switching network. The digitized voice is compressed and stored on a hard disk that maintains the voice mail operating system, system prompts, and greetings, and the messages themselves. A processor controls the compressing, storing, retrieving, forwarding and purging of files. A comprehensive review of exemplary voice mail systems and voice messaging systems is disclosed in U.S. Pat. No. 5,631,948 to Bartholomew et al., the disclosure of which is incorporated in its entirety herein by reference.
The above-incorporated Bartholomew et al. patent discloses a system and method of effecting transfer of a message such as a voice message from one centralized messaging system to another centralized messaging system in a switched communications network having a plurality of central offices connected to subscriber terminals and connected together by trunks. Specifically, the transfer of the message by one centralized messaging system is effected through a common channel signaling network using the existing advanced intelligent network (AIN) implementation of public switched telecommunications networks in the United States. The disclosed voice messaging system provides caller to remote mailbox and/or mailbox to remote mailbox communication using TCAP and SS7 messaging in the AIN while blocking or obviating trunking of voice messages. The disclosed system uses existing voice mail equipment interfaced to the telephone network and that is fully responsive to TCAP and SS7 protocols. In particular, the voice mail system communicates with a service switching point (SSP), which in combination with a centralized node in the network, such as a Service Control Point (SCP), enable AIN services to be provided for the voice mail system.
According to Bartholomew et al., a caller desiring to leave a voice message in the mailbox of a remote person may use a telephone to access his own voice mail system and mailbox and to record the message. The voice processing unit of the mailbox may operate its voice menu to direct the caller to depress a specified key when satisfied with the message. The voice processing unit may then query the caller as to whether he desires to send the message and, if so, to depress another specified key. The voice unit then may instruct the caller as to the procedure for keying in the identity of the destination and to depress a further specified key to send the message. The message is digitized in conventional fashion and stored in the mailbox of the sender. The caller may go on hook after depressing the designated send key. The depression of the send key causes the generation of a tone or other signal which is recognized by the acting SSP as an AIN trigger. This local connection ends usage of the voice network.
The trigger causes the SSP to frame a TCAP inquiry message which is directed to the SCP for instructions. The TCAP message includes information identifying the calling station and mailbox and the called station and the fact that the caller is requesting mailbox to mailbox message transfer. The SCP consults its database to establish whether the caller is authorized to communicate mailbox-to-mailbox and as to the existence and identity of a mailbox for the called number. The SCP then originates a response to the SSP to dispatch one or more SS7 packets to the called directory number and mailbox along with an appropriate routing label and handling instructions and carrying as the included information in the SS7 packet the digitized voice retrieved from the mailbox of the sender. The information may be in T1 protocol which is conventionally the output digital signal of mailbox equipment regardless of manufacture.
Known voice mail systems such as disclosed in Bartholomew et al. are well adapted to efforts to network the voice mail systems. In particular, an organization known as The Message Alliance (TMA) has attempted to establish an open standard for voice mail systems. Work is underway to develop a set of standards known as Audio Message Interchange Service (AMIS) in the hope that when AMIS standards are approved, they will form a common language that network voice mail systems can support to enable communication between voice mail systems of different manufacturers.
In particular, TMA has proposed a voice mail messaging system where a subscriber having voice mail service dials into his or her voice mail system (the originating voice mail system), records a message, and inputs the telephone number (i.e., the destination telephone number) of the called party. The originating voice mail system forwards the message and the input telephone number to a protocol translator. The protocol translator is a node connected to the public switched telephone network and that has a first connection for communication with the originating voice mail system and a second connection dedicated to communication with a centralized database. The protocol translator, implemented for example using an IBM RS 6000 system, converts the message and the corresponding telephone number from the protocol used by the originating voice mail system to a protocol compatible with the centralized database (e.g., AMIS). The protocol translator sends the converted message and telephone number to the centralized database via the second dedicated connection using, for example, an Asynchronous Transport Multiplex (ATM) transport layer.
The proposed TMA database stores telephone numbers for all voice mail boxes for all voice mail systems in the TMA network. Hence, all service providers having voice mail subscribers will have the respective voice mail box information stored in the TMA database. Upon receiving a message from the protocol translator, the TMA database will retrieve necessary information for accessing the voice mail box for the called party based on the supplied telephone number, and supply routing information back to the protocol translator. The protocol translator, using the routing information, then initiates a line-sided connection with the public switched telephone network to establish a connection with a destination node serving the voice mail system for the called party.
The above-described voice mail systems, however, suffer from the disadvantage that a user of the voice mail system must manually key in the destination telephone number for the called party. In particular, the voice processing unit of the voice mail system is configured to detect the destination telephone number based on the sequence of DTMF signals generated during touchkey inputs by the user. Although tolerable by voice mail users who have unimpeded access to a telephone list and a touch-tone pad, this arrangement is not practical for users that do not recall a destination telephone number for a desired individual, or users that prefer "hands-free" operation that avoids the use of a touch-tone pad.
This problem is readily apparent for business travelers that need to check their voice mail messages while traveling. For example, a business traveler may access his or her voice mail box for messages, and discover an urgent voice mail message from a customer. Assume the business traveler wishes to reply to the voice mail message by calling back the customer, or wishes to forward the voice mail message to a colleague to request additional information related to the urgent voice mail message. If the business traveler does not recall the telephone numbers of the colleagues (or have their telephone numbers readily available), the business traveler will need to disconnect from his or her voice mail, access the appropriate directory assistance system to obtain the telephone number of the customer and/or colleague, record the telephone number supplied by the directory assistance system (e.g., by writing the number on a sheet of paper), disconnect from the directory assistance system, and call back the voice mail box to replay the message and manually input the telephone numbers obtained from directory assistance.
This problem exists even in conventional business and residential voice mail systems, where a voice mail subscriber having a voice mailbox on a private branch exchange or computer/answering machine wishes to reply or forward a message on his or her mailbox, and does not have the destination telephone number readily available. Voice mail systems typically have a "time-out" feature, where a voice mail subscriber is disconnected if no reply to a prompt is received by the voice mail system within a prescribed interval. Hence, if the voice mail subscriber attempts to place the voice mailbox on "hold" (e.g., by pressing hook/flash on his or her desk telephone) to access a directory assistance system, there is a risk that the voice mail system will disconnect if the subscriber does not return to enter the destination telephone number within a prescribed time interval.
Hence, voice mail users suffer the inconvenience of remembering, as well as manually inputting, destination telephone numbers in order to reply to voice mail messages, or to forward the voice mail messages. The requirement of manual key inputs is not only an annoyance for voice mail users who do not have the destination telephone numbers readily available, but may also result in voice mail users putting themselves in unsafe conditions, for example if a voice mail user inappropriately attempts to use the keypad of a cellular telephone while driving a vehicle.
Personal electronic directories (PED) have been developed that enable subscribers to access personal directories. For example, U.S. Pat. No. 5,204,894 to Darden, the disclosure of which is incorporated in its entirety herein by reference, discloses a central office based service and apparatus where subscribers may call a special number from any DTMF telephone to access their personal directory. The PED provides subscribers the ability to store names and numbers through audio signals which are preferably the subscriber's voice. In particular, the PED subscriber accesses a voice response unit (VRU), and adds an entry by speaking the first four letters of the name to be stored, followed by speaking the full name, and then speaking the individual digits of the telephone number. The subscriber then may access his PED remotely from any DTMF telephone and have a requested name and number repeated back in the subscriber's own voice by spelling the first four letters of the requested name. As an option the subscriber may have the number automatically dialed.
The Darden system, however, recognizes only clearly spoken letters or numerals, as opposed to spoken names. Moreover, the personal electronic directory requires a user to input individual names and numbers: its scope is limited to those numbers and names input by the user, and does not include the telephone number listings associated with generalized directory systems.
Automated directory assistance systems have been developed that have speech recognition capabilities. Such automated directory assistance systems are beneficial in minimizing the necessity on operator intervention. Examples of automated directory assistance systems are described in U.S. Pat. No. 5,638,425 to Meador, III et al., and U.S. Pat. No. 5,553,119 to McAllister et al., the disclosures of which are incorporated in their entirety by reference. Meador, III et al. discloses a mechanized directory assistance system for use in a telecommunications network, where a caller's response is recognized using various recognition devices; once a match having a satisfactory probability level is obtained, the match is used to access a database for the corresponding telephone number.
Despite the foregoing, voice mail users having a need to obtain a destination number for an intended recipient of a voice mail message (e.g., a forwarded message) must still suspend the voice response session with the voice response unit of the voice mail system in order to obtain the destination number. Regardless of whether the subscriber uses a personalized directory (e.g., as described in Darden), a conventional operator-assisted directory assistance system, or an automated directory assistance system as disclosed in Meador, III et al. or McAllister et al., the voice mail subscriber must access the destination telephone number from the accessed directory, write down the number (or attempt to remember the number) retrieved by the directory system, and return to the voice mail system to enter the destination number.
Hence, the requirement that a voice mail user needs to obtain the desired destination telephone from the directory assistance system, followed by manual input of the destination telephone number into the voice mail system for forwarding the stored voice mail message, results in inconvenience to the voice mail user, and a greater probability of errors due to recording the wrong number or pressing the wrong key. In addition, the above systems are especially inconvenient for users who require hands-free operations.